Mejia pitched seven scoreless innings in his season debut and Daniel Murphy homered twice and tied a career high with five RBIs and the New York Mets defeated the Washington Nationals 11-0 Friday in the opener of a day-night doubleheader.

Murphy went 4 for 5 and added a pair of RBI singles. Juan Lagares had three hits and Ike Davis added a three-run homer for New York, which has won five of seven.

Mejia (1-0), who had been on the disabled list since March with shoulder inflammation, allowed seven hits. He struck out seven with no walks.

"I haven't seen him obviously that good in a long time," manager Terry Collins said. "The command of his stuff was very, very good. His location. I thought he pitched an outstanding game. His best changeup. I didn't know he had one. He used it and used it effectively. He pitched a great game."

Mejia, 23, was 0-4 for the Mets in 2010. He underwent Tommy John surgery in 2011 and spent most of 2012 at Triple-A Buffalo. He was 1-2 with a 6.33 ERA in three September starts for the Mets.

Prior to being recalled for Friday's start, the right-hander went 2-0 in a pair of rehab starts at Double-A Binghamton.

"Certainly it's easy to fall back in the pack," Collins said of Mejia, whom he said will remain with the Mets when they make a roster move after the doubleheader.

"He was the rage in 2010. Everybody thought this guy's, the sky's the limit. And then the injuries have set him way back.

"I give our rehab coordinator, Jon Debus, tremendous credit. When he was rehabbing, (Debus) said, 'There's no reason why your name shouldn't be in the hat. At one time, you were the guy. You were the big dog. Now they're talking (Zack) Wheeler, (Matt) Harvey.' And he said, 'There's no reason why your name shouldn't be in the mix.' And I think today he showed you it should be in the mix."

Steve Lombardozzi and Ryan Zimmerman had two hits apiece for Washington, which was held scoreless a day after its dramatic 9-7 walk-off win over Pittsburgh.

"That means a lot," Mejia said of his performance. "When I was here the first day that I pitched in September last year, I threw like a reliever. But now I come here and my first pitch is like a starter. And I feel I can be a starter now."

Jordan Zimmermann (12-6), who allowed seven runs in a career-low two innings Sunday in a 9-2 loss to the Dodgers, needed 118 pitches to go 6 2-3 innings.